The health effects of tea have been examined ever since the first infusions of Camellia sinensis about 4700 years ago in China. The legendary emperor Shennong claimed in The Divine Farmer's Herb-Root Classic that Camellia sinensis infusions were useful for treating conditions including tumors, abscesses, bladder ailments, and lethargy.
In test tubes, catechins are more powerful than vitamins C and E in halting oxidative damage to cells and appear to have other disease-fighting properties. Studies have found an association between consuming green tea and a reduced risk for several cancers, including, skin, breast, lung, colon, esophageal, and bladder.
The fluoride found in tea has been shown to inhibit the growth of glucosyltransferase. This substance helps the plaque that naturally forms to adhere to our teeth.
Theanine, a component of black tea, has been advocated as a sports supplement . Physical activity causes elevation of the stress hormone cortisol, which could, in theory, interfere with the benefits of exercise by slowing muscle growth.
Faster isn’t better when it comes to health benefits. To get the maximum benefit from your tea, experts suggest steeping a tea bag in water for five minutes. This gives the antioxidants time to be released into your drink.
The best way to get the catechins and other flavonoids in tea is to drink it freshly brewed. Decaffeinated, bottled ready-to-drink tea preparations, and instant teas have less of these compounds. Tea can impede the absorption of iron from fruits and vegetables. Adding lemon or milk or drinking tea between meals will counteract this problem.
Today, green tea is the most popular antioxidant ingredient in natural skin care products. It helps reduce damage from exposure to sun, slow down aging, and clear up skin conditions such as rosacea.
Clinical studies suggest that green tea extract may boost metabolism and help burn fat. One study found that the combination of green tea and caffeine improved weight loss and maintenance in people who were overweight and moderately obese.
Regularly drinking green tea could protect people from Alzheimer’s disease and other forms of dementia as well as cancer, according to a study completed by scientists at Newcastle University, located in northeast England.
Additional benefits for regular consumers of green and black teas include a reduced risk for heart disease. The antioxidants in green, black, and oolong teas can help block the oxidation of LDL (bad) cholesterol, increase HDL (good) cholesterol and improve artery function.
Black and green tea are made from the same plant, but black tea has been allowed to oxidize, altering its constituents. While green tea is high in catechins (especially epigallocatechin gallate, or EGCG), black tea contains relatively high levels of theaflavins, theanine, and thearubigens.